8 3/4 for 74 duster

73 and 74 A-body. You can use 68-72 but you would have to drill your axles and drums for 4 1/2" bolt pattern. I'm not sure about later years. I'm sure someone knows a bit more than myself. I had some 4 1/2"BP Newport axles I had cut down and used the Newport 11" brakes and backing plates in my Big block 68 dart (Heavy) I plan on doing the Jeep Liberty rear disc. conversion hopefully this year.